1. Field of the Invention
The present invention relates to an adhesive medium for the bonding of surfaces in ammunition which contains explosive charges.
For cast or molded explosive charges it is necessary to provide a close fit with the inner wall of the charge carrier. Herein, it is a basic prerequisite that the adhesive medium which provides the adherence with the wall or surface is compatible with the explosive.
2. Discussion of the Prior Art
The heretofore employed adhesive media, which have not been published are constituted on the basis of alkyde resins or bitumins. An adhesive medium which has been internally developed within the applicants' facilities contains an admixture of TNT. The alkyde resins which are employed as binders cure or harden in air or oxygen. When applied to projectile casings that type of adhesive medium will always become harder during storage, such that subsequent to the passage of a certain drying period or storage period, it will be more difficult to attain a dissolution of the adhesive medium onto the explosive during casting, which can be only partially compensated for by a higher preheating temperature of the projectile casing prior to the casting. However, in this instance there are encountered set limits. Namely, when the temperature of the projectile case is higher than the melting temperature of the explosive, then during the casting of TNT, the TNT crystals which are necessary as nuclei formers are always again melted within the smelt, which leads to "coarsely crystalline matrixes", particularly along the edge zone. During the casting of "Composition B" there is retarded the solidification of the TNT, which causes an increased sedimentation of the hexogen. Both effects are not permissible in practice.
Furthermore, the degree of adhesiveness of this adhesive medium is extremely low while the cohesiveness is extremely high. As a consequence, it is disadvantageous that the cast-in explosive will dissolve on the adhesive medium to the desired extent, and in the case of utilization in projectile charges, this will rupture in the boundary layer with the explosive.
In a further adhesive medium which is based on bitumen, there is present the necessary adhesion with the explosives in charge carriers; however, the degree of cohesion is too low. As a result, during firing of the projectile, the layer of the adhesive medium can rupture internally.
Both of the adhesive media are subject to the common disadvantage in that the explosive charge which is cast into the projectile casing will lift away from the projectile base during the cooling phase, and consequently, a base gap can be formed. In such explosive charges the adhesion to the wall or surface which is produced will not be adequate to avoid the relative movement of the explosive charge with respect to the projectile casing during the firing of the projectile. As a result, the explosive charge strikes with an adiabatic compaction of about 200.degree. C. against the bottom of the projectile. This will lead to a spontaneous detonation of the explosive charge in the barrel of the weapon.
For adhesive media which are employed for the bonding of surfaces in ammunition which contain explosive charges, besides providing good properties with respect to adhesiveness and cohesiveness, it is also necessary to demand a rational processing capability.